Probably because that fancafe isn’t Twice’s official one. All JYP artists use the official JYP fancafe so any individual group fancafes are unnofficial 🙂
All SM and JYP Daum fancafes are either unnofficial and/or old. For example, EXO doesn’t use their Daum fancafe anymore and instead use an app (which has over 4 million users). Super Junior, TVXQ, Red Velvet, and SNSD fancafes, though official, have been unused for years.
So a proper list is one that has omitted all JYP and SM fancafes.